From 91f8c421c9941997165d0e7ac1e8c3e81836432d Mon Sep 17 00:00:00 2001 From: amdegregorio Date: Tue, 8 Jan 2019 10:31:20 -0500 Subject: [PATCH 1/8] example code for Article How to Write to a CSV File in Java --- .../com/baeldung/csv/WriteCsvFileExample.java | 29 ++++++ .../csv/WriteCsvFileExampleUnitTest.java | 90 +++++++++++++++++++ .../src/test/resources/exampleOutput.csv | 2 + 3 files changed, 121 insertions(+) create mode 100644 core-java-io/src/main/java/com/baeldung/csv/WriteCsvFileExample.java create mode 100644 core-java-io/src/test/java/com/baeldung/csv/WriteCsvFileExampleUnitTest.java create mode 100644 core-java-io/src/test/resources/exampleOutput.csv diff --git a/core-java-io/src/main/java/com/baeldung/csv/WriteCsvFileExample.java b/core-java-io/src/main/java/com/baeldung/csv/WriteCsvFileExample.java new file mode 100644 index 0000000000..fd3678d2c5 --- /dev/null +++ b/core-java-io/src/main/java/com/baeldung/csv/WriteCsvFileExample.java @@ -0,0 +1,29 @@ +package com.baeldung.csv; + +import java.io.BufferedWriter; +import java.io.IOException; + +public class WriteCsvFileExample { + + public void writeLine(BufferedWriter writer, String[] data) throws IOException { + StringBuilder csvLine = new StringBuilder(); + + for (int i = 0; i < data.length; i++) { + if (i > 0) { + csvLine.append(","); + } + csvLine.append(escapeSpecialCharacters(data[i])); + } + + writer.write(csvLine.toString()); + } + + public String escapeSpecialCharacters(String data) { + String escapedData = data.replaceAll("\\R", " "); + if (data.contains(",") || data.contains("\"") || data.contains("'")) { + data = data.replace("\"", "\"\""); + escapedData = "\"" + data + "\""; + } + return escapedData; + } +} diff --git a/core-java-io/src/test/java/com/baeldung/csv/WriteCsvFileExampleUnitTest.java b/core-java-io/src/test/java/com/baeldung/csv/WriteCsvFileExampleUnitTest.java new file mode 100644 index 0000000000..4ac84f939d --- /dev/null +++ b/core-java-io/src/test/java/com/baeldung/csv/WriteCsvFileExampleUnitTest.java @@ -0,0 +1,90 @@ +package com.baeldung.csv; + +import static org.junit.Assert.assertEquals; +import static org.junit.Assert.assertTrue; + +import java.io.BufferedWriter; +import java.io.File; +import java.io.FileWriter; +import java.io.IOException; +import java.util.ArrayList; +import java.util.Iterator; +import java.util.List; + +import org.junit.Before; +import org.junit.Test; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +public class WriteCsvFileExampleUnitTest { + private static final Logger LOG = LoggerFactory.getLogger(WriteCsvFileExampleUnitTest.class); + + private static final String CSV_FILE_NAME = "src/test/resources/exampleOutput.csv"; + private WriteCsvFileExample csvExample; + + @Before + public void setupClass() { + csvExample = new WriteCsvFileExample(); + } + + @Test + public void givenCommaContainingData_whenEscapeSpecialCharacters_stringReturnedInQuotes() { + String data = "three,two,one"; + String escapedData = csvExample.escapeSpecialCharacters(data); + + String expectedData = "\"three,two,one\""; + assertEquals(expectedData, escapedData); + } + + @Test + public void givenQuoteContainingData_whenEscapeSpecialCharacters_stringReturnedFormatted() { + String data = "She said \"Hello\""; + String escapedData = csvExample.escapeSpecialCharacters(data); + + String expectedData = "\"She said \"\"Hello\"\"\""; + assertEquals(expectedData, escapedData); + } + + @Test + public void givenNewlineContainingData_whenEscapeSpecialCharacters_stringReturnedInQuotes() { + String dataNewline = "This contains\na newline"; + String dataCarriageReturn = "This contains\r\na newline and carriage return"; + String escapedDataNl = csvExample.escapeSpecialCharacters(dataNewline); + String escapedDataCr = csvExample.escapeSpecialCharacters(dataCarriageReturn); + + String expectedData = "This contains a newline"; + assertEquals(expectedData, escapedDataNl); + String expectedDataCr = "This contains a newline and carriage return"; + assertEquals(expectedDataCr, escapedDataCr); + } + + @Test + public void givenNonSpecialData_whenEscapeSpecialCharacters_stringReturnedUnchanged() { + String data = "This is nothing special"; + String returnedData = csvExample.escapeSpecialCharacters(data); + + assertEquals(data, returnedData); + } + + @Test + public void givenBufferedWriter_whenWriteLine_thenOutputCreated() { + List dataLines = new ArrayList(); + dataLines.add(new String[] { "John", "Doe", "38", "Comment Data\nAnother line of comment data" }); + dataLines.add(new String[] { "Jane", "Doe, Jr.", "19", "She said \"I'm being quoted\"" }); + + File csvOutputFile = new File(CSV_FILE_NAME); + try (BufferedWriter writer = new BufferedWriter(new FileWriter(csvOutputFile))) { + for (Iterator dataIterator = dataLines.iterator(); dataIterator.hasNext();) { + csvExample.writeLine(writer, dataIterator.next()); + if (dataIterator.hasNext()) { + writer.newLine(); + } + } + writer.flush(); + } catch (IOException e) { + LOG.error("IOException " + e.getMessage()); + } + + assertTrue(csvOutputFile.exists()); + } +} diff --git a/core-java-io/src/test/resources/exampleOutput.csv b/core-java-io/src/test/resources/exampleOutput.csv new file mode 100644 index 0000000000..45c37f3a3b --- /dev/null +++ b/core-java-io/src/test/resources/exampleOutput.csv @@ -0,0 +1,2 @@ +John,Doe,38,Comment Data Another line of comment data +Jane,"Doe, Jr.",19,"She said ""I'm being quoted""" \ No newline at end of file From 81e2750ee0011d4badb355b87c112177a0e0d333 Mon Sep 17 00:00:00 2001 From: amdegregorio Date: Thu, 10 Jan 2019 10:50:03 -0500 Subject: [PATCH 2/8] Updated to use a Stream --- .../com/baeldung/csv/WriteCsvFileExample.java | 7 ++----- .../csv/WriteCsvFileExampleUnitTest.java | 20 +++++++------------ 2 files changed, 9 insertions(+), 18 deletions(-) diff --git a/core-java-io/src/main/java/com/baeldung/csv/WriteCsvFileExample.java b/core-java-io/src/main/java/com/baeldung/csv/WriteCsvFileExample.java index fd3678d2c5..e1237481b1 100644 --- a/core-java-io/src/main/java/com/baeldung/csv/WriteCsvFileExample.java +++ b/core-java-io/src/main/java/com/baeldung/csv/WriteCsvFileExample.java @@ -1,11 +1,8 @@ package com.baeldung.csv; -import java.io.BufferedWriter; -import java.io.IOException; - public class WriteCsvFileExample { - public void writeLine(BufferedWriter writer, String[] data) throws IOException { + public String convertToCSV(String[] data) { StringBuilder csvLine = new StringBuilder(); for (int i = 0; i < data.length; i++) { @@ -15,7 +12,7 @@ public class WriteCsvFileExample { csvLine.append(escapeSpecialCharacters(data[i])); } - writer.write(csvLine.toString()); + return csvLine.toString(); } public String escapeSpecialCharacters(String data) { diff --git a/core-java-io/src/test/java/com/baeldung/csv/WriteCsvFileExampleUnitTest.java b/core-java-io/src/test/java/com/baeldung/csv/WriteCsvFileExampleUnitTest.java index 4ac84f939d..e30ec0818c 100644 --- a/core-java-io/src/test/java/com/baeldung/csv/WriteCsvFileExampleUnitTest.java +++ b/core-java-io/src/test/java/com/baeldung/csv/WriteCsvFileExampleUnitTest.java @@ -3,12 +3,10 @@ package com.baeldung.csv; import static org.junit.Assert.assertEquals; import static org.junit.Assert.assertTrue; -import java.io.BufferedWriter; import java.io.File; -import java.io.FileWriter; -import java.io.IOException; +import java.io.FileNotFoundException; +import java.io.PrintWriter; import java.util.ArrayList; -import java.util.Iterator; import java.util.List; import org.junit.Before; @@ -73,15 +71,11 @@ public class WriteCsvFileExampleUnitTest { dataLines.add(new String[] { "Jane", "Doe, Jr.", "19", "She said \"I'm being quoted\"" }); File csvOutputFile = new File(CSV_FILE_NAME); - try (BufferedWriter writer = new BufferedWriter(new FileWriter(csvOutputFile))) { - for (Iterator dataIterator = dataLines.iterator(); dataIterator.hasNext();) { - csvExample.writeLine(writer, dataIterator.next()); - if (dataIterator.hasNext()) { - writer.newLine(); - } - } - writer.flush(); - } catch (IOException e) { + try (PrintWriter pw = new PrintWriter(csvOutputFile)) { + dataLines.stream() + .map(csvExample::convertToCSV) + .forEach(pw::println); + } catch (FileNotFoundException e) { LOG.error("IOException " + e.getMessage()); } From 2db589c5b47ee20cbc7b3e82d857bd261938dd0d Mon Sep 17 00:00:00 2001 From: amdegregorio Date: Mon, 14 Jan 2019 13:35:07 -0500 Subject: [PATCH 3/8] Updated to use Streams in convertToCSV for BAEL-2499 --- .../com/baeldung/csv/WriteCsvFileExample.java | 16 ++++++---------- .../csv/WriteCsvFileExampleUnitTest.java | 2 +- 2 files changed, 7 insertions(+), 11 deletions(-) diff --git a/core-java-io/src/main/java/com/baeldung/csv/WriteCsvFileExample.java b/core-java-io/src/main/java/com/baeldung/csv/WriteCsvFileExample.java index e1237481b1..f409d05b06 100644 --- a/core-java-io/src/main/java/com/baeldung/csv/WriteCsvFileExample.java +++ b/core-java-io/src/main/java/com/baeldung/csv/WriteCsvFileExample.java @@ -1,18 +1,14 @@ package com.baeldung.csv; +import java.util.stream.Collectors; +import java.util.stream.Stream; + public class WriteCsvFileExample { public String convertToCSV(String[] data) { - StringBuilder csvLine = new StringBuilder(); - - for (int i = 0; i < data.length; i++) { - if (i > 0) { - csvLine.append(","); - } - csvLine.append(escapeSpecialCharacters(data[i])); - } - - return csvLine.toString(); + return Stream.of(data) + .map(this::escapeSpecialCharacters) + .collect(Collectors.joining(",")); } public String escapeSpecialCharacters(String data) { diff --git a/core-java-io/src/test/java/com/baeldung/csv/WriteCsvFileExampleUnitTest.java b/core-java-io/src/test/java/com/baeldung/csv/WriteCsvFileExampleUnitTest.java index e30ec0818c..0658ec6101 100644 --- a/core-java-io/src/test/java/com/baeldung/csv/WriteCsvFileExampleUnitTest.java +++ b/core-java-io/src/test/java/com/baeldung/csv/WriteCsvFileExampleUnitTest.java @@ -65,7 +65,7 @@ public class WriteCsvFileExampleUnitTest { } @Test - public void givenBufferedWriter_whenWriteLine_thenOutputCreated() { + public void givenDataArray_whenConvertToCSV_thenOutputCreated() { List dataLines = new ArrayList(); dataLines.add(new String[] { "John", "Doe", "38", "Comment Data\nAnother line of comment data" }); dataLines.add(new String[] { "Jane", "Doe, Jr.", "19", "She said \"I'm being quoted\"" }); From 720c32ab78b18e3fc092700e674c4e84724ef33b Mon Sep 17 00:00:00 2001 From: amdegregorio Date: Sat, 26 Jan 2019 09:00:26 -0500 Subject: [PATCH 4/8] BAEL-2542 Creating a Jar - example code --- .../java/com/baeldung/jar/Dimensioner.java | 27 ++++++++++++ .../java/com/baeldung/jar/JarExample.java | 31 +++++++++++++ .../main/java/com/baeldung/jar/Rectangle.java | 44 +++++++++++++++++++ .../resources/META-INF/example_manifest.txt | 1 + .../src/main/resources/files/dimensions.txt | 3 ++ 5 files changed, 106 insertions(+) create mode 100644 core-java/src/main/java/com/baeldung/jar/Dimensioner.java create mode 100644 core-java/src/main/java/com/baeldung/jar/JarExample.java create mode 100644 core-java/src/main/java/com/baeldung/jar/Rectangle.java create mode 100644 core-java/src/main/resources/META-INF/example_manifest.txt create mode 100644 core-java/src/main/resources/files/dimensions.txt diff --git a/core-java/src/main/java/com/baeldung/jar/Dimensioner.java b/core-java/src/main/java/com/baeldung/jar/Dimensioner.java new file mode 100644 index 0000000000..bc5cea4010 --- /dev/null +++ b/core-java/src/main/java/com/baeldung/jar/Dimensioner.java @@ -0,0 +1,27 @@ +package com.baeldung.jar; + +import java.io.BufferedReader; +import java.io.FileNotFoundException; +import java.io.IOException; +import java.io.InputStreamReader; +import java.util.ArrayList; +import java.util.List; + +public class Dimensioner { + + public List loadFromFile(String dimensionFile) throws FileNotFoundException, IOException { + List rectangles = new ArrayList(); + try (BufferedReader br = new BufferedReader(new InputStreamReader(Dimensioner.class.getResourceAsStream(dimensionFile)))) { + String line; + while ((line = br.readLine()) != null) { + String[] dimensions = line.split(","); + if (dimensions.length == 2) { + Rectangle rectangle = new Rectangle(Integer.valueOf(dimensions[0]), Integer.valueOf(dimensions[1])); + rectangles.add(rectangle); + } + } + } + return rectangles; + } + +} diff --git a/core-java/src/main/java/com/baeldung/jar/JarExample.java b/core-java/src/main/java/com/baeldung/jar/JarExample.java new file mode 100644 index 0000000000..262df3a5ec --- /dev/null +++ b/core-java/src/main/java/com/baeldung/jar/JarExample.java @@ -0,0 +1,31 @@ +package com.baeldung.jar; + +import java.io.IOException; +import java.util.List; + +public class JarExample { + private static final String DIMENSION_FILE = "/dimensions.txt"; + + public static void main(String[] args) { + String environment = System.getProperty("environment"); + if (environment != null && environment.equalsIgnoreCase("prod")) { + Dimensioner dimensioner = new Dimensioner(); + try { + List rectangles = dimensioner.loadFromFile(DIMENSION_FILE); + rectangles.forEach(rectangle -> { + rectangle.printArea(); + rectangle.printPerimeter(); + }); + } catch (IOException e) { + System.err.println("Exception loading dimensions"); + } + } else if (args.length > 0) { + int length = Integer.valueOf(args[0]); + int width = (args.length > 1) ? Integer.valueOf(args[1]) : Integer.valueOf(args[0]); + Rectangle rectangle = new Rectangle(length, width); + rectangle.printArea(); + rectangle.printPerimeter(); + } + } + +} diff --git a/core-java/src/main/java/com/baeldung/jar/Rectangle.java b/core-java/src/main/java/com/baeldung/jar/Rectangle.java new file mode 100644 index 0000000000..f2a174c819 --- /dev/null +++ b/core-java/src/main/java/com/baeldung/jar/Rectangle.java @@ -0,0 +1,44 @@ +package com.baeldung.jar; + +public class Rectangle { + private int length; + private int width; + + public Rectangle(int length, int width) { + this.length = length; + this.width = width; + } + + public int area() { + return length * width; + } + + public int perimeter() { + return (length * 2) + (width * 2); + } + + public void printArea() { + System.out.println("Area: " + area()); + } + + public void printPerimeter() { + System.out.println("Perimeter: " + perimeter()); + } + + public int getLength() { + return length; + } + + public void setLength(int length) { + this.length = length; + } + + public int getWidth() { + return width; + } + + public void setWidth(int width) { + this.width = width; + } + +} diff --git a/core-java/src/main/resources/META-INF/example_manifest.txt b/core-java/src/main/resources/META-INF/example_manifest.txt new file mode 100644 index 0000000000..90e83e9b42 --- /dev/null +++ b/core-java/src/main/resources/META-INF/example_manifest.txt @@ -0,0 +1 @@ +Main-Class: com.baeldung.jar.JarExample diff --git a/core-java/src/main/resources/files/dimensions.txt b/core-java/src/main/resources/files/dimensions.txt new file mode 100644 index 0000000000..0397c2a610 --- /dev/null +++ b/core-java/src/main/resources/files/dimensions.txt @@ -0,0 +1,3 @@ +12,16 +24,6 +7,19 \ No newline at end of file From 66c92495fb27780f76c0409408fc38cdcf3f83f4 Mon Sep 17 00:00:00 2001 From: amdegregorio Date: Mon, 28 Jan 2019 06:53:52 -0500 Subject: [PATCH 5/8] BAEL-2542 Update system property name --- core-java/src/main/java/com/baeldung/jar/JarExample.java | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/core-java/src/main/java/com/baeldung/jar/JarExample.java b/core-java/src/main/java/com/baeldung/jar/JarExample.java index 262df3a5ec..daa44025d5 100644 --- a/core-java/src/main/java/com/baeldung/jar/JarExample.java +++ b/core-java/src/main/java/com/baeldung/jar/JarExample.java @@ -7,8 +7,8 @@ public class JarExample { private static final String DIMENSION_FILE = "/dimensions.txt"; public static void main(String[] args) { - String environment = System.getProperty("environment"); - if (environment != null && environment.equalsIgnoreCase("prod")) { + String inputType = System.getProperty("input"); + if (inputType != null && inputType.equalsIgnoreCase("file")) { Dimensioner dimensioner = new Dimensioner(); try { List rectangles = dimensioner.loadFromFile(DIMENSION_FILE); From 499aec3490118b3e9d92264edcc4f8816c5f3abb Mon Sep 17 00:00:00 2001 From: amdegregorio Date: Wed, 30 Jan 2019 13:55:37 -0500 Subject: [PATCH 6/8] updates to simplify example --- .../java/com/baeldung/jar/Dimensioner.java | 27 ------------ .../java/com/baeldung/jar/JarExample.java | 24 +--------- .../main/java/com/baeldung/jar/Rectangle.java | 44 ------------------- 3 files changed, 1 insertion(+), 94 deletions(-) delete mode 100644 core-java/src/main/java/com/baeldung/jar/Dimensioner.java delete mode 100644 core-java/src/main/java/com/baeldung/jar/Rectangle.java diff --git a/core-java/src/main/java/com/baeldung/jar/Dimensioner.java b/core-java/src/main/java/com/baeldung/jar/Dimensioner.java deleted file mode 100644 index bc5cea4010..0000000000 --- a/core-java/src/main/java/com/baeldung/jar/Dimensioner.java +++ /dev/null @@ -1,27 +0,0 @@ -package com.baeldung.jar; - -import java.io.BufferedReader; -import java.io.FileNotFoundException; -import java.io.IOException; -import java.io.InputStreamReader; -import java.util.ArrayList; -import java.util.List; - -public class Dimensioner { - - public List loadFromFile(String dimensionFile) throws FileNotFoundException, IOException { - List rectangles = new ArrayList(); - try (BufferedReader br = new BufferedReader(new InputStreamReader(Dimensioner.class.getResourceAsStream(dimensionFile)))) { - String line; - while ((line = br.readLine()) != null) { - String[] dimensions = line.split(","); - if (dimensions.length == 2) { - Rectangle rectangle = new Rectangle(Integer.valueOf(dimensions[0]), Integer.valueOf(dimensions[1])); - rectangles.add(rectangle); - } - } - } - return rectangles; - } - -} diff --git a/core-java/src/main/java/com/baeldung/jar/JarExample.java b/core-java/src/main/java/com/baeldung/jar/JarExample.java index daa44025d5..5f33188adf 100644 --- a/core-java/src/main/java/com/baeldung/jar/JarExample.java +++ b/core-java/src/main/java/com/baeldung/jar/JarExample.java @@ -1,31 +1,9 @@ package com.baeldung.jar; -import java.io.IOException; -import java.util.List; - public class JarExample { - private static final String DIMENSION_FILE = "/dimensions.txt"; public static void main(String[] args) { - String inputType = System.getProperty("input"); - if (inputType != null && inputType.equalsIgnoreCase("file")) { - Dimensioner dimensioner = new Dimensioner(); - try { - List rectangles = dimensioner.loadFromFile(DIMENSION_FILE); - rectangles.forEach(rectangle -> { - rectangle.printArea(); - rectangle.printPerimeter(); - }); - } catch (IOException e) { - System.err.println("Exception loading dimensions"); - } - } else if (args.length > 0) { - int length = Integer.valueOf(args[0]); - int width = (args.length > 1) ? Integer.valueOf(args[1]) : Integer.valueOf(args[0]); - Rectangle rectangle = new Rectangle(length, width); - rectangle.printArea(); - rectangle.printPerimeter(); - } + System.out.println("Hello Baeldung Reader!"); } } diff --git a/core-java/src/main/java/com/baeldung/jar/Rectangle.java b/core-java/src/main/java/com/baeldung/jar/Rectangle.java deleted file mode 100644 index f2a174c819..0000000000 --- a/core-java/src/main/java/com/baeldung/jar/Rectangle.java +++ /dev/null @@ -1,44 +0,0 @@ -package com.baeldung.jar; - -public class Rectangle { - private int length; - private int width; - - public Rectangle(int length, int width) { - this.length = length; - this.width = width; - } - - public int area() { - return length * width; - } - - public int perimeter() { - return (length * 2) + (width * 2); - } - - public void printArea() { - System.out.println("Area: " + area()); - } - - public void printPerimeter() { - System.out.println("Perimeter: " + perimeter()); - } - - public int getLength() { - return length; - } - - public void setLength(int length) { - this.length = length; - } - - public int getWidth() { - return width; - } - - public void setWidth(int width) { - this.width = width; - } - -} From f324ce902f68bf00edcfabc3784975785e393bf7 Mon Sep 17 00:00:00 2001 From: amdegregorio Date: Fri, 1 Feb 2019 14:34:28 -0500 Subject: [PATCH 7/8] move the manifest into to simplify the example --- .../META-INF => java/com/baeldung/jar}/example_manifest.txt | 0 1 file changed, 0 insertions(+), 0 deletions(-) rename core-java/src/main/{resources/META-INF => java/com/baeldung/jar}/example_manifest.txt (100%) diff --git a/core-java/src/main/resources/META-INF/example_manifest.txt b/core-java/src/main/java/com/baeldung/jar/example_manifest.txt similarity index 100% rename from core-java/src/main/resources/META-INF/example_manifest.txt rename to core-java/src/main/java/com/baeldung/jar/example_manifest.txt From 724139c9df0eab8be24586412953135c83b7effc Mon Sep 17 00:00:00 2001 From: amdegregorio Date: Sat, 2 Feb 2019 06:50:52 -0500 Subject: [PATCH 8/8] clean up unused file --- core-java/src/main/resources/files/dimensions.txt | 3 --- 1 file changed, 3 deletions(-) delete mode 100644 core-java/src/main/resources/files/dimensions.txt diff --git a/core-java/src/main/resources/files/dimensions.txt b/core-java/src/main/resources/files/dimensions.txt deleted file mode 100644 index 0397c2a610..0000000000 --- a/core-java/src/main/resources/files/dimensions.txt +++ /dev/null @@ -1,3 +0,0 @@ -12,16 -24,6 -7,19 \ No newline at end of file